upd78f0124hgba1-8et-a Renesas Electronics Corporation., upd78f0124hgba1-8et-a Datasheet - Page 83

• Manufacturer Part Number: upd78f0124hgba1-8et-a
• Description: 8-bit Single-chip Microcontrollers
• Manufacturer: Renesas Electronics Corporation.

4.2.4 Port 3
using port mode register 3 (PM3). When used as an input port, use of an on-chip pull-up resistor can be specified in
1-bit units by pull-up resistor option register 3 (PU3).
Port 3 is a 4-bit I/O port with an output latch. Port 3 can be set to the input mode or output mode in 1-bit units
This port can also be used for external interrupt request input and timer I/O.
RESET input sets port 3 to input mode.
Figures 4-11 and 4-12 show block diagrams of port 3.
Caution In the
Remark P31/INTP2 and P32/INTP3 of the
PU3:
PM3:
RD:
WR××: Write signal
WR
WR
WR
RD
PORT
when the on-chip debug function is used. For details, refer to CHAPTER 25
FUNCTION (
PU
PM
Pull-up resistor option register 3
Port mode register 3
Read signal
µ
PD78F0124HD, be sure to pull the P31 pin down after reset to prevent malfunction.
µ
PM30 to PM32
PU30 to PU32
PD78F0124HD ONLY).
(P30 to P32)
Output latch
Alternate
function
PU3
PM3
Figure 4-11. Block Diagram of P30 to P32
CHAPTER 4 PORT FUNCTIONS
User’s Manual U16962EJ3V0UD
µ
PD78F0124HD can be used as on-chip debug mode setting pins
EV
DD
P-ch
ON-CHIP DEBUG
P30/INTP1 to
P32/INTP3
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